Spray gun



Sept. 13, 1932.

P. S. CASE S PRAY GUN Filed Feb. 8, 1929 Patented Sept; 13, l1932 UNITED .STATI-1s" rA'lEN-fr oFFlt-:E

PHILIP s. CAsI1,oI` NIAGARA IsAIiLs, NEW YORK, AssIeNoa 'ro ELECTRO EETALLURCI- CAL CoMrANr, A ConronArIoN orywEsr VIRGINIA SPRAY GUN Application mea rebruary s,- Iega. semi Natsasse.

i My invention relates to spraying devices lfor-producing a spray of solids in \suspen sion witha gasrand especially to the production of a spray which may be projected at a low velocity and which'may be homogeneously mixed with a liquid binding material.

A low velocity moist'spray is useful for producing a binderl moistened coating of powdered solids upon fragile objects, such as sand casting molds.

solids. A dry spray is useful to a sorb an excess of binder on the surface of al binder moistened coating or for other pur Voses.

Therefore it is among the /maln'o jects of my invention to provide devices for producing a low velocity spray of solids andfgas.

Another object o vide a device which will homogeneously imf pregnate a low velocity spray of'solids andvl Figure 2 1s a side elevational v iewvof the air distributing ring, v

Figure S-is a cross sectional v1ew of the air distributing `ring taken along thelline III- III of Figure 2,

Figure 4 isa side elevational view of thev emulsifier ring,

, Figure 45 is a cross 'sectional vlew ofthe emulsiiier ring taken ,along the lineV-T-V v of Figure 4,

Figure is a side elevational view of the i nipple member,

' Figure 7 1s an end elevational view of the ni ple member, and

igure 8` is a cross sectional .view of the nipp e member taken along the line VIII#- VIII of Figure 7.'

. The :spray gun may consistjof a'lhandle` portion anda head portion or barrel.; The handle portion may consist of a .serles of pipes or passage means which provide a plasbores in the head y The device may be used to produce a.1ow velocity spra of dry my invention is to prosagegl for solids .and air2 a passage 2 for a mixture'of liquid and air and a passage\3 for air. The passages or conduits through the' handle lead to corresponding passages or consist of a'ceritra pipe 5 carrying a bracket 6 and side lpipes which are carried by the bracket and supported at the ends in a perforated plate 8. Thehead or barrel-portion may be screwed to the plate '8 by a plurality of screws in such a way that the assageway 'will be continuous through t e plate andhead.

In the barrel or 'head of the gun the mixture ofl solids and airare discharged from a central port which is the terminus of the passageyl. The liquid and air mixture is conducted through the passage 2 and an emulportion. The handle may siier and isdischarged through a series ofi portsl() which causev the atomized' liquid to 7 surround the atomized solids. The airis conducted through an Aair shut off andregulatmgvalve 7, the passage 3' 'andan equalizer ports 11 into the stream ofsolids and air so as to agitate the mixture. By reason of this jectedp-mixtures with respect' to 'eakch `other, the fmixtures and the air combine external of yinto the head and is discharged through the l i 7.5

-agitatinand of the disposition of the pro-l the gun and form-a spray of suspended solids `so Thel solids are supplied to the gun as a n stream or cloud of solids suspendedu in air. This suspension 'of atomized solids may be produced bmyany suitable means externalof the gun Vprovided the suspension is .homogeneous and the velocity of the stream is suit'- v, able .Vfor the purpose intended, This Inixtre^ is. usually conducted to the gunvthrough ay 90.

flexible .hose 12 which dischargesint the central pipe (5. In'order tonprevent: rapidv erosion of the metal ofthe ipe a resilient lining 13 may be provided by inserting agum .95

:rubber hose snugly inthe paissagel and extending it to thevexit'- port inthe head. TheJ lining may be secured by'insertin'g a tapered ring' 14 intol the end f the hose and then screwing down the reducer 11.5 sothat the hose oo yWill be wedged' between the head of the pipe.

v needed. Air is supplied to the mixer from a isc suitable source through the branch 16 and liquid is supplied under pressure through the branch 17. Valves 18 and 19 in the branches 16 and 17 are used to vary the mixture of liquid and air and to discontinue the mixture when it is not needed. rl`he branch pipes 16 and 17 are disposed at an angle of about 30 from each other and at the point of union of the pipes a comparatively large amount of air is usually mixed with a small amount of liquid. rl`he liquid is then carried by the air through the passagev 2 into the emulsier which is contained in the gun head.

A reduced portion cuts across the passage 2 near the end of the gun head and the emulsier. is mounted upon this reduced portion. Another reduced portion cutting the passage 3 is formed near the end of the gun head and a-,gasy equalizer is mounted on this portion.

rlhe latter reduced portion is threaded so as to screw on a recessed nipple 20 whichis'so recessed as to provide chambers and passages.`

The unreduced portion of the head is threaded and the cap 21 is screwed on. rll`he cap extends over the extremity of the nip le member and acts as a stop or lock there or. The cap encloses the nipple member 20 and forms the outside walls of the air equalizing chamber.

, f'lhe emulsier chamber 22 is formed Within the `.inner recessed portion of the nipplemember 20 and the reduced end portion 23 of the gun head. A. ring 24, having grooves 25 extending to the outer edges of the ring, is slidably mounted in the chamber 22 and is cut to a size so as to provide a narrowsr` annular passage 26 between the outer margin of the ring and the inner threaded surface of the nipple member. The ring 24 is provided with radial or other inclined grooves 25 extending from its inner to its outer edges. When the mixture of liquid and air is passed from the` passage 2'through the chamber 27 and around the ring, the tortuous and restricted path ortned by the grooved ring causes a violent mixing or emulsifying of the li uid and-air.

The ring 24 may be grooved on oth sides if desired but grooving on the side which comes in contact with the nipple member is* al1 that is necessary. When grooves are provided on both sides of the ring the groovesmay be staggered as shown in Figure 5,. The staggering of the` grooves in the ring provides 'a spiral path for the liquid passing around the ndtched edges of the ring. I prefer to groove the ring on both sides if for no other reason than to insure proper mounting of nevegeic face of the reduced section of the gun` head` I may be made to provide a preliminary distributing chamber and an annular passage around the barrel. The innermost bore 30 of the ring 24 is preferably given a sliding it. 0n the reduced end vsection of the gun head.

Discharge ports. 10 are formed between the gun head and the nipple member. l may orm the ports 10 in the nipple member by cutting longitudinal grooves therein as shown in Figures 7 and 8 but the grooves may be formed in the outer surface of the reduced portion of the barrel and they may be disposed spirally if so desired. At all events, the ports 10 are arranged so that the projected atomized mixture of liquid and air Will form a cylindrical envelope around the discharged mixture of solids and air. .ln order to prevent a divergently directed envelope of liquid and air, a shallow7 annular groove-32 having an arcuate cross section is cutnear the end ofthe barrel. As the mixture of liquid and air flows from the edge of this groove it s impelled slightly toward fthe axis of the arrel.

i rlhe air passage 3 `1s cut across by a second reduced portion of the head and an annular groove 35 is formed' in the face of the cut lso as to provide an annular passage through Which the air from the passage 3 may be distributed. A. distributing ring 36 is screwed on the reduced portion of the barrel so as to form the front wall of the annular passage 35 and the rear wall of ari' intermediate distributing chamber 37. Spaced ports 38 are formed in the ring so as to distribute the air -approximately equally in the intermediate chamber 37. The ports 38 may consist of equally spaced erforations in the .ring 36 but better distri ution results when one portion of the ring 36 is left unperforated and vthe unperforated portion is spaced as a baile directly in front of the air passage 3. An un- 10;

perforated portion 39 subtending an angle of about 30 at the center of the ring has given good results but the bame may be of greater or less extent. In order to give the most effective distribution of air around the annular The largest external cylindrical portion of the nipple member 20 is given a sliding-.fit in the cap 21 and equally spaced passages 41 are extended from the intermedia-te chamber 37 to an annular outer or discharge chamber 42.

l :los

The passagesl may be formed by the groovesl 41 in the surface of the nip le member.

The grooves 41 redistri ute and" equalize the air still further and th are preferably l disposed spirally s o as to swirl the air in the chamber 42 and cause it to cut across the small ports l1 which ane spaced near the end of the nipple member and are directed at an angle to the stream of mixed solids and air.

The ports 11 are preferably,dlrectedrradif ally in a plane perpendicular tothe axis of the head so that a curtain of air will be produced throu h which solids will pass and by means of which they will be violently agitated. The 15 rports l1 ma Ibe inclined' obliquely to the axis of the hea but'betterspraying results are generally obtained with the o'rts directed rpendicularly tothe axis. 'gbmevariation 1n the inclinationo the jets oair may be ob tained by adjusti g the nipple member 204V out orin so that theair will "impingeinore or less against the end surface 44 of the head. The ports 11 are situated in a portion of the nipple member which extends beyond the end of the barrel. The nipple is' proportioned so that it can be/srewed outwardly or inwardly and produce impingementor restriction of the jets discharged from the ports'll;

The nipple is held or locked in the adj usted so position by screwing down'thecap 21 so that i it will bear against the end` surface 43 ofthe nipple member t The above described spray gun finds its c principal use inv/.applications which require 85 a low velocity spray of solids or of moistened solids, but it is evident that higher velocities may beused. As a general rule, the mixture of solids and air of the desired consistency is produced at the nozzle and then the liquid and air mixture and the air are Nadjusted to i give the wetness andcharapcter pf spraydesired. A dry sprayof mixed powder and a-irf` is sometimes` y desired. Such a spray may be produced by closing the'valves 18 and 19.

45 Although Ihave described one specific eml bodiment of my Iinvention it is evident that /variousimodiications of my device may be l made within the scope of my invention'f,

Therefore, I wishto be limited only by the prior art and bythe invention as defined inl y the appended claims. f

-'I claim as my inventionL n A,

1L A spray gun comprising `means to form a mixture'of liquid and gas'ka handle por- 7tion'havin a conduit for conductinga `inix tyre of solids and gasfand a conduit for conducting gas,/a' heady portion liaving passage coextensiveflwith saidcdnduits,l a dischargeport forv the solids and as and a phllurality 60, of an'nuarly disposed'l ischarge .ports for j .gasjsaid head havin apassge for donductara ture equallyl to the annularly disposed dis-,\ charge means and means in said gas passage" -to distribute gas equally to the plurality of annularly 'dis osed discharge ports, said passage for sollds and gas being disposed axially in said head and said discharge for the gas and the mixture of liquid and gas being arranged to discharge gie same in the viinity of the discharge mixture of solids and gas so as toform a mixture externally of the head.

2.. Af-spray gun comprising ahead having a bore for conducting a mixture of solids and gas, a bore for conducting a mixture of liqj uid and gas and a'bore for conducting gas, a@ cap'on the head and a recessed nipple member 'on the head forming with the cap an intermediate gas chamber, a discharge gas chaiber and a communication between the chambers, said nipple member' having discharge orifices communicating with the dis 'charge chamber.

3. A spray gun) comprising a head having a central bore 'fdr conducting arinixture oi:v solids and gas, a bore for conducting a mixture of liquid and gas and a bore for 'con-rJ ducting gas, a reduced l`end portion in the' headcuttmg across said borefor liquid and gas, a recessed nipple-member on thel head formingla liquid and gas chambercommunieating with one of saidbores, means in said ychamber to form a` tortuous passage in the` chamber, said reducedportionof the head being adapted to slide into the nipple `niember, saidanipplemember and reduced vportion forming a discharge means communiwith the liquid and gas chamber; spray gup comprising'a head having a borefbr conducting amixture of solids and gas, a bore forconducting a mixture of liquid and gas and a gas passage, a cap on the head, a recessed nip le member forming with the cap an interm diate gaschamber-and a discharge gas chamber and a ring secured in the 'intermedi ate chamber, said head'having an annular passage communicating with the gas passage, said ring havlng passages communicating with th annular passage `and i the intermediate chamber, and said recessed lnipple member having "passagesextending f l between'the chambers.

l 5. A spray n comprising a head lhavin a bore for con liftingl a mixtureof solids an gas, a' bore for conducting a. mixture of liquid and gas and a gas passageqa cap onfthe head,V Ial recessed j nipple member' `forming with lthe cap v an'intermediate 'chamber,a discharge chamber and a communication bes `Ltween said chambers,a perforatedring in the intermediate chamber having" an unper foratedportion opposite the end of said gas ing saidmixture of iquid and gas and disapassage, said head having an annularA groove communicating lwith the witlr said ,perforations gas passage and 6. A spray gun comprising a barrel mm?v n ber having a central axially disposed bore 'for conducting a mixture of solids and gas, a bore for conducting a mixture of liquid and gas and a bore for conducting gas, a cap on the barrel and a recessed nipple member forming with the cap a discharge gas chamber, said nipple member extending beyond said barrel and having spaced orifices in the extension communicating with the discharge gas chamber, and arranged to discharge gas into the solid-air mixture external of the head.

7. A spray gun comprising a barrel member having a central axially disposed bore for conducting a mixture of solids and gas, a bore for conducting a mixture of liquid and gas and a bore for conducting gas, a cap on the barrel and a recessed nipple member forming with the cap a discharge gas cham; ber, said nipple member extending beyond said barrel and having a plurality of equally spaced orices communicating with the discharge chamber and arranged to discharge gas into the solid-gas mixture external of the barrel and at an angle to the direction of flow of the solidair mixture.`

8. A spray gun comprising a head having a centrally disposed conduit for a mixture of solids and gas, a bore for conducting gas and a bore forconducting a' mixture of liquid and gas, said head having reduced sections cutting acrossv said bores, a recessed nipple member secured to one of said reduced sections and an outerI cap on the hea-d engaging the nipple member and forming a'lock therefor,

o said nipple member having an inner recessed portion and grooves in an inner face thereof which form a' chamber and exit ports be-I tween the nipple member 'and the head, outer recesses and grooves in the nipple member which form gas passages and chambers bey `tween the nipple member and cap, and openings in the nipple member which communicate with 'oneof the gas chambers and form gas discharge ports.

9. A spray gun comprising a head having a centrally disposed port for discharging a 'mixture ofsolids and gas, a gas bore, -discharge ports for` gas and a bore for conducting a mixture of liquid and gas, said head having a reduced end portion which vcomprisesa face cutting across the liquid-gas bore, another reduced portion of the head' cutting across the gas bore, a nipple'member having a face in slidin len agement with the Yreduced end portion o the eadV and an inner 'recess in the nipple membern adjustable engagement with saidother reduced ortion of the head, said recessed portion of t eI nip-` ple member and the end reducedportio'n' of the head forming a chamber around the head in` communication withy the'liq'uid-gas bore 'l the end portion of the nipple member an said reduced end ortion ofthe nipple memher forming a dis arge means yfor liquid and Levaeio gas mixture between the nipple member and the head.

10. A spray gun comprising a head having*` a centrally disposed port for discharging a mixture of solids and gas, a gas .bore, discharge ports for gas and a bore for conductinga mixture of liquid and gas, said head having a reduced end portion which com` prises a face cutting across the liquid-gas bore, another reduced portion of the head cutting across the gas bore, a bored nipple member having an inner grooved face in slidy ing engagement Withv the said reduced end portion of the head and an inner recess having an adjustable engagement With said other reduced portion of the head, said recessed portion ofthe nipple member and `other reduced portionv of the head forming a chamber around the head in communication with said' liquid-gas bore and the grooved face of said nipple member forming discharge ports for liquid and gas mixture between the nipple member and the head. l y e `11. A spray gun comprising a handle portion carrying a liquid and gas mixer, a conduit for gas, a conduit for a mixture of li uid and gas and a conduit for a mixture of so ids and gas, ahead portion having borescoextensive with the conduits of the handle and a centrally disposed port for discharging the solid and gas mixture, an obstruction in the liquid-gas bore whereby the direction of flow of the liquid and gas is changed so as to in'- tersperse one into the other, and an end portion of the head having ports spaced-therearound and in communication with the liquidgas bore for discharging the mixture of interspersed liquid and gas.

12. A spray gun comprising a handle portion carrying a liquid and gas mixer,a conduit for gas, aconduit for amixture of liquid and gas and a conduit for a mixture of solids and gas, a hhead portion having bores coextensive With the conduits of the handlev and a centrally disposed port for discharging the solid, and gas mixture, an obstruction in the liquid-gas conduit'whereb the direction of flow of the liquid and gas 1s changed so as to intersperse one into the other and obstructions and chambers in the gas conduit to equally distribute gas annularly in the head.

13. A spray gun comprising a handle portion carrying a liquid and gas mixer, a conduit for gas, a conduit for liquid and as mixture and a conduit for a mixture of solids and gas, a head portion having bores coex- 'tensive with the conduits of the handle and aport for discharging a mixture or' solids 1 g y and gas, a cap on the head, a nipple, member on the head recessed so as to form within the cap an outer gas chamber, an'inner gas chamberand a communication between thechambers, an -air distributing member on the head having spaced ports communicating with a supply of gas under pressure and with said inner chamber, said nipple member having gas discharge ports communicating with the outer chamber and directed so as to project converging currents of gas into the discharged mixture of solids and gas. Y

1-5. A spray gun comprising a head having a port for discharging a mixture of solids and gas, a cap on the head, a nipplel member on the head recessed so as to form an outer gas chamber and an inner gas chamber within the cap, said'nipple member having grooves j in the outer surface which form communications between said chambers, a ring on the' head havingspaced openings thereinvvhich communicatewith a source of gas under pressure and with the inner chamber, said nipple 'member having discharge ports communicat-l ing withthe outer chamber and directed so as to proj ect-converging currents of gas into the 4discharged mixture of solids and gas'. 16. A'spray gun comprising a barrel inember having a central port for discharging a mixture of solids and gas, a gas passage, a

cap on Ithe barrel, a nipple member project- Y ing beyond the barrel, said nipple member belng recessed so as to form an end chamber and having gas discharge ports in the projecting portion which communicate with the end chamber, said barrel having a reduced portion which forms an equalizing chamer with the cap and nipple member, a gas equalizer on saird reduced portion havlng ports communicating with the gas passage and with the equalizing chamber, means 'in said Areduced portion to adjust the lnipple member so as to move the discharge ports out I `or inpwith respect to the end of the barrel and means o n the cap to lock the nipple member i in its adjusted position.

v17. A spray gun comprlsing a head having .8, centrally disposed port for dischargingV a spray ofy solids and gas and a bore for'con ducting gas, said head'having arreduced section which orms a face cuttin gas conducting bore, the face eing channeled to form a passage around the head which communicates with the bore, .a rin on the reduced sectionbearing against said ace, a recessed nipple member on said reduced sec- 18. I A spray gun comprising a head having i i a centrally disposed port for discharging a spra of solids and gas and a bore for conductin gas, said head having a reduced sec.

justments, and a cap on thehead engaging the nipple so as to lock the same in itsadjusted position, said cap forming inner and louter chambers with the vrecessed nipple member and spiral passages between the chambers,

said ring forming one Wall of the inner chaml ber and having small spaced communications between the channel and inner chamber. In testimony whereof I aix my signature.

HILIP S. CASE.

across4 the tion capable of being adjusted inwardly and outwardly/on the head and a cap on the head' engagingthe end of said nipple member so' as to lockthe same in its adjusted positionv and to" form'inner and outer chambers and passages between the chambers said ring" forming onev wall of the inner chamber and ,having acommuncation between said chan-- n el and inner chamber, f 

